Cellulose organic derivative compositions containing tetrahydrofurfuryl tetrahydrofuroate



Patented Jan. 9, 1940 UNITED STATES PATENT came GELLULOSE ORGANIC DERIVATIVE COM- POSITIONS CONTAINING TETRAHYDRO- FURFURYL TETRAHYDROFUROA'IE Joseph B. Dickey and James B. Normington, Rochester, N. Y., assignors to Eastman {Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application March 31, 1939,

Serial No. 265,230

5 Claims (Cl. 106-40) graphic film, molding compounds-and products,

artificial silk, varnishes or lacquers, coating compositions, interlayers for laminated glass, and

the like.

One object of this invention is to produce compositions of matter which may be made into permanently transparent, strong and flexible sheets 20 or films of desired thinness which are substantially waterproof, are unaffected by ordinary photographic fluids and possess the desired properties of a support for sensitive photographic coatings. Another object of our invention is to pro- 25 duce compositions of matter which are capable of .easy and convenient manipulation in the plastic and analogous arts, such as in the manufacture of sheets, film, artificial silk filaments, varnishes, lacquers and the like, and to produce com- 30 positions which will not injure, or be injured by, the substances or surfaces with which they are associated during manufacture. Another object of our invention is to produce compositions which can be molded at elevated temperatures and high 35 pressures to produce plastic products having the desirable properties of hardness, toughness and "elasticity. Still another object of our invention is to produce interlayers for laminated glass which retain their properties of toughness and elasticity at low temperatures. Other objects will become apparent to those skilled in the art to which this invention pertains.

We have discovered that valuable properties may be induced in and/or contributed to com- 45 positions containing organic derivatives of cellulose, such as cellulose organic acid esters and cellulose ethers, by adding thereto, as a plasticizing compound, tetrahydrofurfuryl tetrahydrofuroate. This compound and a method of pre- 5 paring it are described and claimed in the copending application of Joseph B. Dickey and James G. McNally, Serial No. 247,094, filed December 21, 1938. The-particularly useful properties which it induces in or contributes to cellulosic compositions containing it are hereinafter enumerated. i

In order that those skilled in this art may better understand our invention we would state, by way of illustration, that for the manufacture of 60 photographic film base or other sheets our new compositions of matter maybe compounded as follows: 100 parts of acetone-soluble cellulose acetate, 1. e., cellulose acetate containing from about 36% to 42% acetyl radical, approximately, is dissolved with stirringat atmospheric temperature in 300 to 500 parts, preferably 400 parts, by weight, of acetone. To this, solution may be added from to 50 parts by weight of tetrahydrofurfuryl tetrahydrofuroate. Within the limits stated, the

amount of plasticizer may be decreased or increased, depending upon whether it is desired to decrease or increase, respectively, the properties which this plasticizer contributes to the finished product. The amount of solvent employed may also be increased or decreased, depending upon whether it is desired to have a more or less freely flowing composition, respectively' A composition of matter prepared as above described may be deposited upon any suitable filmforming surface and the. acetone-evaporated therefrom to form a film or sheet, in a manner well known to those skilled in the art. A film so produced has permanently brilliant transparency and low infiammability, burning no more readily than ordinary newsprint. Films or sheets produced in accordance with our invention are very tough and flexible, and maintain flexibility in a superior fashion.

Other volatile solvents which are compatible with the cellulose acetate and our new plasticizer will also occur to those skilled in this art, such as ethylene, chloride-alcohol mixtures, ethylene chloride-dioxan mixtures, etc. In like manner this plasticizer may be compounded with other single organic acid esters of cellulose, such as cellulose propionate, butyrai e, stearate and the like, or with mixed organic atzid esters, such as cellulose acetate-stearate, cellulose acetate-propionate, cellulose acetate-butyrate, cellulose acetatelactate, cellulose acetate-tartrate and the like, or with cellulose ethers, such, for instance, as ethyl cellulose and benzyl cellulose, a suitable solvent which will dissolve both the cellulosic derivative and the plasticizer being employed: for example, an alkylene chloride with or without the addition of an alcohol, or one of the many known volatile solvents for cellulose ethers. For instance, cellulose acetate-propionate and tetrahydrofurfuryl tetrahydrofuroate may be dissolved in ethylene chloride or in a mixture of propylene chloride and methanol, and sheets of excellent flexibility may be deposited from these solutions. Other substances, such as fire-retardants, evaporation retardants, etc., may be added to the film-forming compositions.

Tetrahydrofurfuryl tetrahydrofuroate may also be advantageously used as a plasticizer in cellulose organic derivative molding compositions. For instance, from 25 to 150 parts of the plasticizer, depending on the hardness or softness of the plastic desired, may be homogeneously mixed with cellulose acetate, and the mixture converted into a transparent plastic product by molding at a temperature of 140160 C. and a pressure of 2,500 to 4,000 pounds per square inch for a. period of from 2 to minutes, in a manner Well known to those skilled in molding compounds of that nature. The softer plastics may be extruded through a die. Interlayers for laminated glass may be deposited from a solvent, or formed by extrusion with or without the use of a volatile solvent. Products containing tetrahydrofurfuryl tetrahydrofuroate show excellent properties even at a temperature of F. For instance, interlayers for laminated glass, prepared from various samples of cellulose acetate and varying proportions of tetrahydrofurfuryl tetrahydrofuroate, showedthe following properties at --10 F.

Parts by weight tetra Yield point Tensilestrength hydrofuriuryl tetra (kgs) of strip Gigs.) of strip Percent hydrofuloate per 100 mm. wide 15 mm. Wlde stretch Parts by Weight celluand 0.0085 and 0.0085

ose acetate inch thick inch thick Tetrahydroiurfmyl tetrahydrofuroate is a solvent for ethyl cellulose at room temperature.

What we claim as our invention and desire to be secured by Letters Patent of the United States 1. A composition of matter comprising a cellulose organic derivative and tetrahydrofurfuryl tetrahydroiuroate as a plasticizer therefor.

2. A transparent, flexible sheet comprising parts by weight of a cellulose organic derivative and from 5 to parts by weight, approximately, of tetrahydrofurfuryl tetrahydrofuroate as a plasticizer therefor.

3. A composition of matter comprising a cellulose organic acid ester and tetrahydrofurfuryl tetrahydrofuroate as a plasticizer therefor.

4. A composition of matter comprising a cellulose ether and tetrahydrofurfmyl tetrahydrofuroate as a plasticizer therefor.

5. A transparent, flexible sheet, having the properties of toughness and elasticity at low temperatures, comprising 100 parts by weight of a cellulose acetate and from 100 to 150 parts by weight, approximately, of tetrahydrofurfuryl tetrahydrofuroate as a plasticizer therefor.

JOSEPEIE. DICKEY. JAMES B. NORMINGTON. 

